Beach Water Sampling

<p>Five water samples per beach are collected weekly on Tuesdays during the swimming season and tested for E. coli bacteria. Results take at least 18 hours to receive and can range from 0 to a maximum of 1000 E. coli per 100mL. The geometric mean (GM) E. coli per 100mL is calculated for each beach from the five samples and posted on Wednesdays. If the regular weekly sample GM at a beach is greater than 400 E. coli per 100mL, resampling will be done at that beach in the same week. Resampling will also be done if a sampling error (for example, due to delay in receipt of the sample at the lab) occurs with the regular weekly sample. Any available resampling results are posted on Fridays.</p><p><strong>Date created: </strong>June 17, 2026<br /><strong>Update frequency: </strong>Wednesdays and Fridays from June through August.<br /><strong>Accuracy: </strong>No known errors. Points of consideration for interpretation of the data:&nbsp;<br />&nbsp;</p><ul><li>Prior to 2025, beach water samples were collected daily during the swimming season.</li><li>Prior to 2026, resampling only occurred due to sampling error.</li><li>If the GM is 200 E. coli per 100mL of water or less, the sample meets the standard set in the Ontario Recreational Water Guideline.&nbsp;</li><li>If the GM is more than 200 E. coli per 100mL, the sample does not meet the standard. High E. coli in recreational water may increase the chances of stomach illnesses and skin, eye or ear infections for people swimming or wading, especially children.&nbsp;<br />Sampling of beach water provides a snapshot of water quality at the time it was taken, but the water quality can change quickly depending on environmental conditions. Be aware of conditions and make an informed decision before<br />&nbsp;</li></ul><p><strong>Attributes - Data fields:</strong></p><ul><li>Beach, Sampling date (DD-MMM-YY), GM E. coli</li></ul><p><br /><strong>Author: </strong>Blayr Kelly<br /><strong>Author email: </strong><a href='mailto:[e-mail]' rel='nofollow ugc'>[e-mail]</a></p><p><strong>Maintainer Organization: </strong>Ottawa Public Health<br />&nbsp;</p>